按照我对此运算符(operator)的早期理解,如果操作数(operand)“expr1”和“expr2”同时为真时,那么上面的代码片段将会执行任何位于if语句块中的内容。这是绝对正确的,并且恰好也是如此工作。唯一的蹊跷是,究竟幕后实际发生了什么。根据Mozilla的JavaScript文档对逻辑运算符(logical operators)的说明。 (逻辑与)若expr1可...
5) 逻辑运算符(Logical operators [ˈlɑ:dʒɪkl]) 6) 字符串运算符(String operators) 7) 条件(三元)运算符(Conditional operator [kənˈdɪʃənəl) 8) 逗号运算符(Comma operator [ˈkɑ:mə]) 9) 一元运算符(Unary operators [ˈju:nəri]) 10) 关系运算符(Relational...
2.赋值运算符(Assignment operators) 3. 逻辑运算符 (Logical operators) 4.比较运算符(Comparison operators) 5.位运算符(Bitwise operators) 6.字符串运算符(String operators) 7. 逗号运算符 (Comma operator) 8.关系运算符(Relational operator) 9.一元运算符(Unary operators) 10. 条件(三元)运算符 (Condi...
The logical AND operator && returns true if both the expressions are true. For example,let x = 2; // both expressions are true console.log((x < 4) && (4 >= x)); // true // only one expression is true console.log((x <= 4) && (2 == 4)); // false // both expressions...
<!doctype html> JavaScript logical AND operator example h1 { color:red; border-bottom: 3px groove silver; padding-bottom: 8px; } JavaScript equal operator (==) example
Logical Operators 逻辑运算符通常用于Boolean型(逻辑)值。这种情况,它们返回一个布尔型值。然而,&&和||运算符实际上返回一个指定操作数的值,因此这些运算符也用于非布尔型,它们返回一个非布尔型值。 描述 下面是逻辑运算符的说明: Operator Usage Description Logical AND (&&) expr1 && expr2 Returns expr1 ...
ECMAScript 6 (ECMA-262)Logical NOT operator ECMAScript 6 (ECMA-262)Binary Logical Operators Release Candidate 浏览器兼容性 Desktop Mobile FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari 逻辑与 (&&) (Yes) (Yes) (Yes) (Yes) (Yes) 逻辑或 (||) (Yes) (Yes) (Yes) (Yes) (Yes) ...
// Logical AND operationtrue&&true;// truetrue&&false;// falsefalse&&true;// falsefalse&&false;// false// Logical OR operationtrue||true;// truetrue||false;// truefalse||true;// truefalse||false;// false If applied to boolean values, the&&operator only returnstruewhen both of its op...
TheJavaScript logical AND operatorcan also be used to set default values. Instead of returning the first true value, the logical AND operatorreturns the first false valueit finds (looking from left to right). If there is no false value, then the last value is returned. Let’s look at the...
If you add a number and a string, the result will be a string! JavaScript Logical Operators OperatorDescription &&logical and ||logical or !logical not Note Logical operators are fully described in theJS Comparisonschapter. JavaScript Type Operators ...